For many years now automotive engine head gasket have utilized sealing wires for surrounding and assisting in the sealing at engine combustion openings. Wires of a variety of materials and positioned with gasket bodies and/or armors in a variety of configurations have been used. Typically solid wires of circular cross-section have been used. These have usually been made of steel, although other materials have been used from time to time as well.
Wires of configurations other than circular in cross-section have been suggested for use as well. For example, the wire of Pohl U.S. Pat. No. 3,606,361 defines a body which is generally rectangular in cross-section, with sharp edged annular profiles generally centrally of the body for pressing into the cylinder block and cylinder head. These profiles appear to be intended to permanently deface the block and head to provide seals at the sharp edges.
A wide range of concerns face the gasket designer, particularly with today's lighter weight engines, and with engines fabricated from materials and masses of material which are much more prone to distortion in operation than were the conventional engines and materials of ten, twenty and thirty years ago. Today those circumstances and conditions such as thermal push present serious problems in designing effective combustion seals. Other circumstances, such as possible bore distortion resulting from gasket design, must also be taken into consideration.
Thus, improved designs for head gaskets and for mechanisms for effectively sealing at combustion openings are to be desired and are actively sought after.